Tech Line VD-170, Service Manual, Page: 7 / 68

1-3-2 DVD_SFNP
Chassis or Secondary Conductor
d d'
Primary Circuit Terminals
AC Voltmeter
(High Impedance)
Exposed Accessible Part
B
One side of
Power Cord Plug Prongs
Z
Safety Check after Servicing
Examine the area surrounding the repaired location
for damage or deterioration. Observe that screws,
parts, and wires have been returned to their original
positions. Afterwards, do the following tests and con-
firm the specified values to verify compliance with
safety standards.
1. Clearance Distance
When replacing primary circuit components, confirm
specified clearance distance (d) and (d’) between sol-
dered terminals, and between terminals and surround-
ing metallic parts. (See Fig. 1)
Table 1 : Ratings for selected area
Note: This table is unofficial and for reference only.
Be sure to confirm the precise values.
2. Leakage Current Test
Confirm the specified (or lower) leakage current
between B (earth ground, power cord plug prongs)
and externally exposed accessible parts (RF termi-
nals, antenna terminals, video and audio input and
output terminals, microphone jacks, earphone jacks,
etc.) is lower than or equal to the specified value in the
table below.
Measuring Method (Power ON) :
Insert load Z between B (earth ground, power cord
plug prongs) and exposed accessible parts. Use an
AC voltmeter to measure across the terminals of load
Z. See Fig. 2 and the following table.
AC Line Voltage Clearance Distance (d), (d’)
220 to 240 V
≥
3 mm(d)
≥
6 mm(d’)
Table 2: Leakage current ratings for selected areas
Note: This table is unofficial and for reference only. Be sure to confirm the precise values.
AC Line Voltage Load Z Leakage Current (i)
One side of power cord plug
prongs (B) to:
220 to 240 V
2k
Ω
RES.
Connected in
parallel
i
≤
0.7mA AC Peak
i
≤
2mA DC
RF or
Antenna terminals
50k
Ω
RES.
Connected in
parallel
i
≤
0.7mA AC Peak
i
≤
2mA DC
A/V Input, Output
Fig. 1
Fig. 2